What had Paul told Israel earlier about going to the Gentiles?
Paul had earlier told Israel that if they would not believe, they would go to the Gentiles. He repeatedly turned to the Gentiles during his ministry, yet he still returned to appeal to Israel, until this final declaration in Rome made it permanent.
Les explains that Paul, while in Rome in prison, declares that the salvation of God is sent to the Gentiles. Earlier in his ministry, Paul had told Israel that if they would not believe, he would go to the Gentiles. He did so repeatedly, but he would still come back and appeal to the nation of Israel. Now, however, this is final. Paul says, "Therefore let it be known unto you, that the salvation of God is sent to the Gentiles, and they will hear it." It does not say they will all believe, but they will hear. After Paul said these words, the Jews departed and had great reasoning among themselves. Les points out this marks a departure in Paul's writings—the Gospel of Grace written to the Church.